(a) Technical Field
The present invention relates to an air supply device using a cooling water heater of a fuel cell vehicle, more particularly, to an air supply device using a cooling water heater of a fuel cell vehicle, which can effectively reduce cold starting time of the fuel cell vehicle and effectively remove moisture in a stack in cold shut down (CSD) of the fuel cell vehicle.
(b) Description of the Related Art
Recently, car manufacturers have had great interest in hydrogen fuel cell vehicles as green vehicles. Many problems remain to be solved with regard to the development of hydrogen fuel cell vehicles. Among these problems, a particularly difficult problem is to guarantee cold starting capability.
In order to facilitate cold starting of a fuel cell vehicle, cooling water is not circulated into a stack in cold starting of the fuel cell vehicle. This is for the purpose of allowing the cooling water not to flow into the stack. Therefore, a cooling water heater (i.e., a heater for heating cooling water) that is an essential component of cooling water circulation is turned off in the cold starting, and the cold starting is delayed due to non-operation of the heater.
In this state, the current of the stack is consumed by operating an air blower or the like in order to induce the stack to generate heat. This has a problem of causing noise and energy loss through air exhaust.
In cold shut down (CSD) of an existing fuel cell vehicle, moisture generated during driving is removed by variably supplying, to a stack, air passing through an air blower and a humidifier, depending on a temperature of cooling water. In this state, when the moisture is not effectively discharged as air from the stack, this has a negative influence on subsequent cold starting of the fuel cell vehicle.
In particular, if the air supplied to the stack in the cold starting of the fuel cell vehicle is cooled by passing through the humidifier, the temperature raising speed of the stack and the air are reduced. As a result, the cold starting of the fuel cell vehicle is delayed, where the cold starting of the fuel cell stack is completed based on the exit temperature cooling water and air.
In the loop structure of a inline connection cooling system of pump-heater-stack, if a heater is operated in cold starting or regenerative braking, a problem is caused in that the heater is damaged due to overheating as long as cooling water is not circulated.